All 20 people on board an old-time propeller plane were killed Saturday after the aircraft crashed in the Swiss Alps, authorities told Swiss media.

Police in southeastern Graubuenden canton said the JU-Air’s JU-52 HB-HOT aircraft crashed on the Piz Segnas mountain above the Swiss Alpine resort of Flims, a place popular with hikers. The plane holds 17 passengers, two pilots and a flight attendant.

“The JU-Air team is deeply saddened and is thinking of the passengers, the crew and families and friends of the victims,” JU-Air wrote in a statement on its website Sunday.